L'acoustique passive appliquée à l'étude du comportement des corégones (Coregonus sp. et C. Lavaretus) durant la reproduction en milieu naturel

L'acoustique passive (étude des bruits propres du milieu environnant) constitue une méthode simple, sinon facile, d'étude de l'activité et du comportement de la faune aquatique.Nous décrivons ici les systèmes de prise de son et d'analyse utilisés à cet effet à l'Institut de Limnologie (Thonon-les-Bains) et rapportons certains résultats d'observations réalisées sur les zones de fraie des corégones (Coregonus lavaretus) du lac d'Aiguebelette et des ombles chevaliers (Salvelinus alpinus du lac d'Annecy : l'activité de fraie des corégones est caractérisée par des bruits brefs (0,5 à 2 s) de type "stridulation"; certains bruits de "fouille" sur substrat d'une omblière semblent directement associés à l'activité prédatrice des lottes (Lota lota) sur la ponte.Listening to underwater sound is a simple way of studying the activity and behaviour of aquatic fauna.The material used in the Institute of Limnology (Thonon-les-Bains) for recording and analysing sounds is described (figure 2). Experiments have been performed on the spawning sites of coregonids (Coregonus lavaretus) in Lake Aiguebelette and of charrs (Salvelinus alpinus) in Lake Annecy. This paper refers mainly to observations made in December 1987 on the site of "Roc de Chère" in Lake Annecy; this is where the charrs spawn and the site is easy to survey (figure 1). Most of the work consisted in continuous visual and acoustical observations, in order to determine the origin of the sounds recorded. A great part of the period was noisy because of water disturbance (wind-induced waves).The most interesting aspect is the study of sounds produced by fish (figure 3). We could not record the activity of the charrs, because of the inconvenient area studied : the observation field was limited to 1 sq.metre, which is very small in comparison to the spawning zone (figure 1). The presence of burbot (Lota lota) in the field of the video camera suggested that these fish came and ate the charr eggs which had been deposited on the bottom. This hypothesis was confirmed by the continuous digging activity (which was heard and recorded) due to the burbot feeding and by an analysis of the stomacal content of specimens, caught white SCUBA diving, which contained fertile eggs. Though acoustically evident, burbot activity was not analysed.The coregonids found in Lake Annecy (1987) (C. species) have the same behaviour as those found in Lake Aiguebelette (1986) (C. lavaretus, a different species). Typical, short (0.5-2 s) stridulating noises are produced during courtship, when the male and the female rub against each other; these noises, nearly always the same, have been analysed (figure 4). The loudest sounds emitted are in the 100-300 Hz range.Another aspect of fish activity has been studied : the noise made by coregonids swimming (figure 4). During courtship, fish is very active and swims energetically. The low frequency of the sound has been recorded by using a special electronic device.All these observations are in accordance with the results presented in the literature. Acoustical observation is an interesting method which should be developed

Atherothrombosis as a Leading Cause of Acute Coronary Syndromes and Stroke: The Main Killers in Developed Countries

Worldwide, cardiovascular incidents are estimated to cause 17.5 million deaths, 80% of which are ischemic strokes or acute coronary syndromes. Cardiovascular disease results in a significant financial burden for healthcare system—namely, in 2009, it was 9% of the gross health service expenditure in the European Union. Therefore, the development of the knowledge about atherosclerosis—initially thought to be solely degenerative disorder but now considered a multifactorial inflammatory state—is essential. Acute coronary syndrome (ACS) is usually a manifestation of severe reduction in coronary blood flow caused by atherosclerotic plaque and thrombus. The pathology of the atherosclerotic plaque is complex. Essentially, it is disease of the arterial intima that, through subsequent stages, results to luminal narrowing. Over the years, various theories regarding the genesis growth and vulnerability of atherosclerotic lesions have been promoted, usually focusing on endothelial injury, smooth muscle cell proliferation, lipid accumulation, and, more recently, inflammatory reactions

The supreme turbinate and the drainage of the posterior ethmoids: a computed tomographic study

Background: It is generally acknowledged that the posterior ethmoidal cells drain under the superior nasal turbinate (SorNT) or, rarely, under the supreme nasal turbinate (SmeNT), and the sphenoid ostium (SO) opens to the sphenoethmoidal recess. However, detailed relations between these structures are variable, complex and still not clear. There is no reliable data on the prevalence of SmeNT and drainage of the posterior ethmoidal cells under this structure. The aim of this study was to re-evaluate the anatomy of the aforementioned region. Materials and methods: Multiplanar and three-dimensional reconstruction analysis of 100 thin slice paranasal sinus computed tomography scans. Results: SmeNT was identified in 77 subjects (136 sides). It formed the ostium to the posterior ethmoidal cell adjacent to the skull base or orbit in 58 subjects (91 sides). This cell drained independently from the remaining posterior ethmoidal cells. The sphenoethmoidal (Onodi) cell drained to supreme meatus in 41 subjects (54 sides), and to superior meatus in 37 subjects (49 sides). SO was always located medial to the posteroinferior attachment of SmeNT, or SorNT (in absence of SmeNT). Conclusions: Patients with divergent drainage of the posterior ethmoids (with posterior ethmoidal cell draining to the supreme meatus) may require more extensive surgery to avoid persistence or recurrence of inflammatory disease. SmeNT is more common than thought, but due to its posterior and superior location to SorNT, it is rarely seen intraoperatively. If SmeNT is present, SO is always located medial to its posteroinferior attachment. (Folia Morphol 2018; 77, 1: 110–115

Preparation and characterization of novel polymer-based gel electrolyte for dye-sensitized solar cells based on poly(vinylidene fluoride-cohexafluoropropylene) and poly(acrylonitrile-cobutadiene) or poly(dimethylsiloxane) bis(3-aminopropyl) copolymers

Polymer gel electrolytes based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(acrylonitrile-co-butadiene) (PAB) or poly(dimethylsiloxane) bis(3-aminopropyl)-terminated (PDES-bAP) copolymers were prepared and investigated in dye-sensitized solar cells (DSSCs). Selected optical and electrochemical properties of all compositions with various ratio from 9:1 to 6:4 were investigated towards DSSC applications. The highest value of power conversion efficiency equal to 5.07% was found for DSSCs containing a PVDF-HPF:PAB (9:1) gel electrolyte. Compositions of electrolytes were additionally tested by electrochemical impedance spectroscopy. The influence of the ratio and type of polymers used as an additive to PVDF-HPF on absorption wavelengths, energy gap, and Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) levels were investigated. Individual components of DSSCs, such as the TiO2 layer and platinum nanoparticles, were imaged by scanning electron microscope. Finally, a DSSC module with six electrically separated solar cells with a 7 × 80 mm2 active area was constructed based on gel electrolytes and tested. © 2020 by the authors

Examination of silver-graphite lithographically printed resistive strain sensors

This paper reports the design and manufacture of three differing types of resistive strain sensitive structures fabricated using the Conductive Lithographic Film (CLF) printing process. The structures, utilising two inks prepared with silver and graphite particulates as the conductive phase, have been analysed to determine electrical and mechanical properties with respect to strain, temperature and humidity when deposited on four alternative substrate materials (GlossArt, PolyArt, Teslin and Melinex)

Electrostatic considerations affecting the calculated HOMO-LUMO gap in protein molecules.

A detailed study of energy differences between the highest occupied and lowest unoccupied molecular orbitals (HOMO-LUMO gaps) in protein systems and water clusters is presented. Recent work questioning the applicability of Kohn-Sham density-functional theory to proteins and large water clusters (E. Rudberg, J. Phys.: Condens. Mat. 2012, 24, 072202) has demonstrated vanishing HOMO-LUMO gaps for these systems, which is generally attributed to the treatment of exchange in the functional used. The present work shows that the vanishing gap is, in fact, an electrostatic artefact of the method used to prepare the system. Practical solutions for ensuring the gap is maintained when the system size is increased are demonstrated. This work has important implications for the use of large-scale density-functional theory in biomolecular systems, particularly in the simulation of photoemission, optical absorption and electronic transport, all of which depend critically on differences between energies of molecular orbitals.Comment: 13 pages, 4 figure

In Vitro

The aim of the presented study was to examine the antimicrobial activity of ethanol extract of Polish propolis (EEPP) against biofilm-forming CoNS strains in vitro. Our results revealed that EEPP displayed varying degrees of activity against CoNS with MIC values ranging from 1.56 to 0.78 mg/mL. The average MIC was 1.13 ± 0.39 mg/mL while calculated MIC50 and MIC90 values were 0.78 mg/mL and 1.56 mg/mL, respectively. The biofilm formation ability by all tested S. epidermidis strains was inhibited at EEPP concentrations ranging from 0.39 to 1.56 mg/mL. The degree of reduction of AlamarBlue was directly associated with the proliferation of S. epidermidis strains. The increased proliferation of S. epidermidis strains was observed after 12 and 24 hours of incubation in the presence of EEPP concentrations ranging from 0.025 to 0.39 mg/mL. These results suggest that antimicrobial activities of EEPP against S. epidermidis expressed as the reduction of bacterial growth, reduction of biofilm formation ability, and the intensity of proliferation were significantly affected by incubation time and EEPP concentration used as well as the interactions between these factors